JP2017506717A - Method for removing leaked crankcase fluid from crankcase and crankcase ventilation system - Google Patents

Abstract

Leaky crankcase fluid is removed from a crankcase during operation of an internal combustion engine. A method of removing leaked crankcase fluid includes a step (S1) of measuring an operating parameter value (308) of an internal combustion engine (100), and an internal combustion engine (100) operating the measured operating parameter value (208). A step (S2) of comparing with a predetermined parameter range (306) defining an operation mode of the internal combustion engine (100) to determine whether the internal combustion engine (100) is in the operation mode. When it is determined, the step (S4) of introducing a leaked crankcase fluid from the crankcase (217) to the intake air (203) of the internal combustion engine (100), and when it is determined that the internal combustion engine is not in the operation mode, 217) directing the leaked crankcase fluid from the internal combustion engine (100) to the surrounding environment (S5). [Selection] Figure 2

Description

  The present invention relates to a method for removing leaked crankcase fluid from a crankcase of an internal combustion engine. The present invention also relates to a crankcase ventilation system and a control unit for controlling an electrically controlled valve of the crankcase ventilation system. The present invention is applicable to vehicles, particularly large vehicles such as trucks. However, although the present invention has been described mainly with respect to trucks, the present invention is of course applicable to internal combustion engines used in other types of vehicles such as passenger cars, industrial construction machines, wheel loaders, and the like. .

  A frequent problem with various types of internal combustion engines is vapor leakage in the crankcase during operation from the combustion process of the engine. These vapor leaks need to be handled in a sufficient and efficient manner so that the leaks are discharged from the crankcase. Since this adversely affects the environment, provides safety issues and adversely affects fuel consumption, it may not be appropriate to redirect vapor to the fuel tank and not to the environment. For this reason, it is desirable to introduce vapor leakage directly into the internal combustion engine so that it can be safely burned and partially used for power generation.

  According to an example, WO 2012/171593 discloses a fuel system for supplying fuel vapor to an internal combustion engine. The fuel system includes a housing that is refilled with lubricant at a constant fill level. During operation of the internal combustion engine to which the fuel system is connected, fuel vapor from the housing is introduced into the combustion chamber of the internal combustion engine. The system further includes a drain valve and a lubricant supply valve. When the engine is not operating, i.e. when the engine is stopped, these valves close, thus preventing fuel leakage from the housing. As a result, when the engine stops due to insufficient negative pressure at the intake port of the engine, the fuel vapor discharge may not function, so WO2012 / 171593 reduces the risk of oil leakage when the engine stops To solve the problem.

  However, the invention disclosed in WO2012 / 171593 requires further improvements, for example with respect to enhancing functionality and oil supply control.

International Publication No. 2012/171593 Pamphlet

  It is an object of the present invention to provide a method for removing leaked crankcase fluid formed in a crankcase of an internal combustion engine. The object is at least partly achieved by the method according to claim 1.

  According to a first aspect of the present invention, a method is provided for removing leaked crankcase fluid from a crankcase of an internal combustion engine during operation of the internal combustion engine. The method includes the steps of measuring an operating parameter value of the internal combustion engine, and a predetermined parameter that defines the operating mode of the internal combustion engine to determine whether the measured operating parameter value is in the operating mode. Comparing the range, guiding the leaked crankcase fluid from the crankcase to the intake of the internal combustion engine when it is determined that the internal combustion engine is in the operating mode, and the internal combustion engine not in the operating mode The leakage of the crankcase fluid from the crankcase to the ambient environment of the internal combustion engine.

  The term “operating parameter” is to be interpreted in the following as a parameter of the internal combustion engine, measured when the internal combustion engine is running, ie when the internal combustion engine is operated, throughout the entire description. . Also, the term “default parameter range” refers to a parameter range according to a measured parameter value, for example, so that a comparison between an operating parameter value and a default parameter range is made for similar parameters. Should be interpreted. Further, according to an exemplary embodiment, the predetermined parameter range is determined by the engine as expected under certain conditions when the engine is operating in normal operation, i.e. at the particular point in time when the measurement was made. Should be construed as the range defining the mode of operation of the engine.

  Also, the term “leaky crankcase fluid” should not be construed as being limited to a particular phase or type of fluid. The leaky crankcase fluid may be in the gas phase or liquid phase. The leaky crankcase fluid can include, for example, blow-by gas, fuel vapor, oil mist, and the like. Furthermore, the leaky crankcase fluid is the fluid generated in the crankcase during operation of the internal combustion engine, i.e. during the combustion process.

  As an example, as described below, for example, when the parameter is related to the exhaust temperature, the method according to the present invention measures the exhaust temperature at a specific time. The measured exhaust temperature is then compared with a predetermined parameter range defining the operating mode of the internal combustion engine, which in a particular example is the temperature range in which the exhaust is expected to be exposed under current engine operating conditions. The In this example, therefore, the operating mode is a predetermined temperature range. If the measured temperature is not within the range, it is determined that the internal combustion engine is not in the operating mode, and the leaked crankcase fluid is directed to the environment surrounding the internal combustion engine instead of the intake air of the internal combustion engine.

  It should be readily understood that the predetermined parameter range can be changed depending on the specific parameters measured. In practice, the range can be made small enough so that it can be considered a specific value.

  The present invention directs leakage crankcase fluid from the crankcase to one of the intake air of the internal combustion engine or the surrounding environment of the internal combustion engine so that it is excessive and controlled with respect to the internal combustion engine even when the engine is not operating in normal operating conditions. Not based on insights that can prevent fuel inhalation. Therefore, the present invention has the advantage that combustion of crankcase leakage of the internal combustion engine is enabled, and power is generated and vehicle emissions can be kept low in the normal operation mode of the internal combustion engine. The present invention provides an efficient engine runaway protection system and allows safe use of a fuel vent-free design. Thus, the crankcase ventilation system is provided to direct leaked crankcase fluid to one of the intake air of the internal combustion engine or the surrounding environment of the internal combustion engine, depending on engine conditions.

  Also, the ambient environment of the internal combustion engine should be interpreted as a position outside the engine and its associated components. This location does not necessarily have to be ambient air, for example, but can be similar to a waste oil collection device or other suitable arrangement for collecting fuel.

  According to an exemplary embodiment, when the internal combustion engine is in the operating mode, it can be determined that the internal combustion engine indicates the normal operating mode.

  In this way, the method distinguishes between operating modes in which the engine is operating as expected, i.e. normal operating modes, and operating modes in which the engine is not operating as expected, i.e. abnormal operating modes. Can do.

  According to an exemplary embodiment, the engine can exhibit a normal operating mode if the measured operating parameter value is within a predetermined parameter range. The advantage is that a well-defined spectrum is provided that the measured parameter value should take in order to determine that the engine exhibits a normal mode of operation. If the engine parameter value exceeds the upper limit value of the range, it is determined that the engine does not indicate a normal operation mode, that is, indicates an abnormal operation mode. Similarly, if the operating parameter value is lower than the lower limit value of the predetermined parameter range, it can be determined that the internal combustion engine does not indicate the normal operating mode. The predetermined parameter range may be, for example, a range extending from a lower end point value that is zero to a certain allowable upper limit value. In such a case, if the measured parameter value exceeds the range, the engine indicates an abnormal operation mode. Thus, the range is defined by an upper threshold, and if the measured operating parameter value exceeds the upper threshold, the engine indicates an abnormal operating mode. According to another example, the range can be a specific value with a predetermined tolerance so that the normal operating mode is defined as being within tolerance.

  According to an exemplary embodiment, the step of directing leaked crankcase fluid from the crankcase to the intake air of the internal combustion engine can be performed by controlling a valve.

  This makes it possible to control the valve so that the leaked crankcase fluid can pass through the valve, or in the closed state where the leaky crankcase fluid cannot pass through the valve. The valve can be controlled by a control unit that further receives information related to the measured parameter value. This allows the control unit to control the valve to open or close depending on the received measured parameter value and the comparison made between the measured parameter value and the predetermined parameter range. it can. For this reason, the control unit can also determine a predetermined parameter range. Alternatively, the control unit may be provided with data relating to the predetermined parameter range from the other control unit (s) of the vehicle. According to one example, the valve is normally in the open state.

  According to an exemplary embodiment, the valve can be located downstream of the crankcase such that the valve is disposed in fluid communication with the intake of the internal combustion engine.

  According to an exemplary embodiment, the step of directing the leaked crankcase fluid from the crankcase to the ambient environment of the internal combustion engine includes from the crankcase fluid in a relief valve disposed in fluid communication between the crankcase and the ambient environment. This can be done by controlling the valve so that the pressure exceeds a predetermined threshold limit.

  The relief valve can desirably be controlled by the pressure to which it is exposed. This prevents leakage crankcase fluid from passing through the valve, i.e., controlling the valve so that the valve is in the closed position, the pressure of the relief valve will eventually be in the open position. To the size you want. Accordingly, the relief valve is desirably located in fluid communication between the crankcase and the valve.

  The relief valve, of course, instead of the aforementioned automatically pressure controlled valve, when leaked crankcase fluid is led from the crankcase to the surrounding environment, the control unit controls the relief valve to open it, It can be controlled by the control unit so that the leaky crankcase fluid passes.

  According to an exemplary embodiment, the operating parameter value may be one of crankcase pressure, engine speed, and exhaust temperature, or any combination thereof.

  These parameters of the internal combustion engine are well known and easy to measure. Also, if these parameter values are not within the range defining the normal operating mode, the leaked crankcase fluid from the crankcase has characteristics that are not suitable for being provided to the internal combustion engine. It should be readily understood that depending on the specific parameters, measurements need to be made at specific locations on the engine. For example, the exhaust temperature may be different at different positions in the exhaust path, so it is important to measure the exhaust temperature at a predetermined temperature range position, that is, a position corresponding to a position that defines a normal temperature range. It is.

  According to a second aspect of the present invention, a crankcase ventilation system is provided for removing leaked crankcase fluid from a crankcase of an internal combustion engine. The crankcase ventilation system includes a valve configured to be in fluid communication with a crankcase of an internal combustion engine and an intake air of the internal combustion engine, and a control unit connectable to the valve. An engine operating parameter value is received, and the received operating parameter value is compared with a predetermined parameter range defining the operating mode of the internal combustion engine to determine whether the internal combustion engine is in the operating mode, and the internal combustion engine is in the operating mode Is determined, the valve is controlled to guide leakage crankcase fluid from the crankcase to the intake of the internal combustion engine, and when it is determined that the internal combustion engine is not in the operation mode, the valve is controlled to Configured to direct leaked crankcase fluid to the surrounding environment.

  An advantage of the system according to the second aspect of the present invention is that a combination of open and closed crankcase ventilation systems is provided. Therefore, if the leaked crankcase fluid is directed to the intake air of the internal combustion engine, the crankcase ventilation system will be a closed crankcase ventilation system, while if the leaked crankcase fluid is directed to the surrounding environment, the crankcase ventilation will be The system is an open crankcase ventilation system.

  According to an exemplary embodiment, the control unit can be configured to place the valve in an open state when it is determined that the internal combustion engine is in an operating mode. As a result, the crankcase fluid is guided from the crankcase through the valve to the intake air of the internal combustion engine.

  According to an exemplary embodiment, the crankcase ventilation system further comprises a relief valve configured to be placed in fluid communication between the crankcase and an outlet to the ambient environment of the internal combustion engine, wherein the internal combustion engine operates. When it is determined that the mode is not set, leakage crankcase fluid from the crankcase is configured to be guided through the relief valve.

  Therefore, when the valve is in the closed state, the leaked crankcase fluid is guided to the relief valve, and when the pressure of the relief valve exceeds the threshold pressure, the relief valve opens and the leaky crankcase fluid opens. The relief valve is controlled by a valve that is directed to the surrounding environment through the relief valve.

  According to an exemplary embodiment, the crankcase ventilation system further comprises an oil mist separator and the valve is located downstream of the oil mist separator.

  According to an exemplary embodiment, the valve can form an integrated part of an oil mist separator. This eliminates the need for individual connection points for the valve, for example, to the vehicle frame. Therefore, integrating the crankcase ventilation system into the oil mist separator does not involve any additional changes to the vehicle connecting the oil mist separator, thus reducing the overall cost of the crankcase ventilation system.

  The relief valve can also be located downstream of the oil mist separator. According to an exemplary embodiment, the relief valve can form part of an oil mist separator.

  By placing the crankcase ventilation system in combination with an oil separator, the leaked crankcase fluid from the crankcase is relatively clean and removes particles that can adversely affect the environment. Thus, providing an oil mist separator offers the advantage of reducing the need for external or additional waste oil collection devices or other devices for collecting fuel.

  According to an exemplary embodiment, the crankcase ventilation system may further comprise a pilot valve configured to position the valve in an open or closed state. According to an exemplary embodiment, the pilot valve can be connectable to the control unit and is configured to position the valve in an open state or a closed state in response to a signal received from the control unit. be able to. Further, according to an example, the pilot valve can be configured to position the valve in an open state or a closed state by pressure generated by intake air of the internal combustion engine.

  The advantage of using a pilot valve is that the pilot valve further controls the opening and closing of the valve.

  The pilot valve can also control other energy sources of the vehicle, such as an engine air brake system.

  According to an exemplary embodiment, the crankcase ventilation system may further comprise a bypass valve disposed in fluid communication between the valve and the intake air of the internal combustion engine.

  The bypass valve can further prevent unwanted leaky crankcase fluid from sucking into the internal combustion engine. This allows the bypass valve to operate as a backup valve in case the valve does not function properly. The bypass valve is adapted to be partially closed when the difference between the crankcase pressure and the intake air pressure of the internal combustion engine is greater than a predetermined threshold pressure value.

  The further effects and features of this second aspect are largely similar to those described above with respect to the first aspect of the present invention.

  According to a third aspect of the present invention, there is provided a control unit that can be electrically connected to a valve of a crankcase ventilation system of an internal combustion engine. The control unit receives the operating parameter value of the internal combustion engine, compares the received operating parameter value with a predetermined parameter range that defines the operating mode of the internal combustion engine, determines whether the internal combustion engine is in the operating mode, When it is determined that the engine is in the operation mode, the valve is controlled to guide the leaked crankcase fluid from the crankcase to the intake air of the internal combustion engine. Configured to direct leaked crankcase fluid to the environment.

  The effects and features of this third aspect are largely similar to those described above with respect to the first and second aspects of the present invention.

  According to a fourth aspect of the present invention there is provided an internal combustion engine comprising a crankcase ventilation system according to any of the exemplary embodiments described above.

  The effects and features of this fourth aspect are largely similar to those described above with respect to the first, second and third aspects of the present invention.

  According to a fifth aspect of the present invention, a crankcase ventilation system is provided for removing leaked crankcase fluid from a crankcase of an internal combustion engine. The crankcase ventilation system is positioned downstream of the crankcase, and is configured to be disposed in fluid communication between the crankcase and the intake air of the internal combustion engine, and is positioned downstream of the oil mist separator. A mist separator, a relief valve configured to be disposed in fluid communication with the intake air of the internal combustion engine and the surrounding environment of the internal combustion engine.

  The advantage of the fifth aspect of the present invention is that, for example, when the crankcase pressure rises due to malfunction of the crankcase ventilation system, the relief valve is positioned in the open state by the increased fluid pressure to which the relief valve is exposed. As a result, when the relief valve is in the open state, the crankcase pressure is reduced, and the vehicle can function properly. Further, the fifth aspect of the present invention is not able to guide the leaked crankcase fluid to the intake air of the internal combustion engine by the frozen conduit, so that, for example, when the conduit to the intake air of the internal combustion engine is frozen due to a cold air condition. Advantageously, the relief valve is exposed to elevated pressure, which automatically places it in an open state and directs leaky crank fluid to the surrounding environment.

  Thus, a fifth aspect of the present invention provides a closed crankcase ventilation system that can be automatically transformed into an open crankcase ventilation system. Thus, the fifth aspect allows the use of a closed crankcase ventilation system even in cold climates where it is desired to use an open crankcase ventilation system in advance.

  The above solution for a closed crankcase ventilation system utilizes a pressure sensor that warns the driver that the crankcase pressure is rising. If the driver does not reduce the crankcase pressure, the vehicle cannot function properly and must transition to a “limp home mode” where it can be secured.

  The fifth aspect of the invention can of course be combined with any of the features described above with respect to the first, second, third and fourth aspects of the invention. The advantages of such a feature in combination with the fifth aspect are largely similar to those described above.

  Additional features and advantages of the invention will be apparent from a review of the appended claims and the following description. Those skilled in the art will appreciate that different features of the present invention can be combined to create embodiments other than those described below without departing from the scope of the present invention.

  The foregoing will be better understood through the following exemplary and non-limiting detailed description of exemplary embodiments of the invention, as well as additional objects, features and advantages of the invention. .

1 is a side view of a vehicle equipped with an internal combustion engine equipped with a crankcase ventilation system according to an exemplary embodiment of the present invention. 1 is a schematic diagram of a crankcase ventilation system according to an exemplary embodiment of the present invention. FIG. It is a figure which shows an example of the temperature measured as a function of time, and predetermined temperature. 4 is a flowchart illustrating method steps according to an exemplary embodiment of the present invention.

  The invention will now be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention. However, the present invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for thorough and completeness. Like reference numerals refer to like components throughout the description.

  With particular reference to FIG. 1, there is provided a vehicle 1 equipped with an internal combustion engine 100 with a crankcase ventilation system according to the present invention. The vehicle 1 shown in FIG. 1 is a truck in which an inventive internal combustion engine 100 and a crankcase ventilation system, which will be described in detail below, are particularly suitable.

  FIG. 2 illustrates an engine system according to an exemplary embodiment of the present invention. The engine system includes a fuel system 201. The fuel system 201 can contain any fuel suitable for a particular engine type. Accordingly, the fuel system 201 can include diesel fuel, gasoline, ethanol, dimethyl ether (DME), and the like. The present invention should therefore not be limited to the specific fuel type driving the engine. The engine system also includes a cylinder arrangement 202 having a crankcase 217 that houses a crankshaft connected to a plurality of pistons via respective connecting rods. The fuel from the fuel tank 201 is guided to the engine via the oil trap 214. According to an example, the additional oil trap 215 may be located between the oil trap 214 and the fuel tank 201 as shown in FIG. The engine system also includes a crankcase ventilation system 206, which will be described in detail below, and a turbo unit including a turbine and a compressor. More specifically, the conduit 209 connects the crankcase ventilation system 206 to the internal combustion engine through the intake 203 and even the inlet of the internal combustion engine.

  Reference is now made to the crankcase ventilation system 206 of the present invention shown in FIG. According to the non-limiting example shown in FIG. 2, the crankcase ventilation system 206 includes an oil mist separator 204, a relief valve 208, a valve 210 electrically connected to the control unit 211, and an optional bypass valve 216. And comprising. The oil mist separator 204 is connected to the blow-by passage 205 and is disposed downstream of the crankcase. The relief valve 208 is further disposed downstream of the oil mist separator 204 in fluid communication between the oil mist separator 204 and the environment surrounding the internal combustion engine. Relief valve 208 should be construed as a valve that is open when exposed to a pressure that exceeds a predetermined pressure limit. The valve 210 is disposed downstream of the oil mist separator 204 and fluidly communicates the oil mist separator and the intake air 203 of the internal combustion engine. Finally, an optional bypass valve 216 is located downstream of the valve 210 and provides fluid communication between the valve 210 and the intake air 203 of the internal combustion engine.

  Further, the valve 210 may be a controllable valve positioned in a valve open state or a valve closed state by a signal from the control unit 211. The controllable valve can be, for example, a two-way valve.

  The function of the crankcase ventilation system 206 and related methods will now be described in more detail. For this reason, reference is made to FIGS.

  For example, when there is a fluid leak generated in the crankcase 217 from the combustion process of the internal combustion engine, the crankcase fluid leak is led out from the crankcase through the blow-by passage 205 and introduced into the mist oil separator 204. In the oil mist separator 204, the leaked crankcase fluid is supplied to the separation process so that the fluid exiting the oil mist separator 204 is free or relatively free from particles that can adversely affect the environment. Accordingly, the fluid leaving the oil mist separator 204 and entering the conduit 207 is relatively clean. The leaky crankcase fluid is then directed to valve 210 or relief valve 208.

  In order to determine if leaky crankcase fluid is to be directed through valve 210 or relief valve 208, the present invention determines whether the internal combustion engine is operating according to normal or abnormal operating modes. This determination is shown in FIG. 3 and gives an example related to exhaust temperature 302 relative to time 304. Accordingly, FIG. 3 shows the change in exhaust temperature over time when the vehicle is traveling. It should be noted that the graph shown in FIG. 3 is only useful for illustrative purposes.

  The solid line 306 in FIG. 3 shows the default parameter range 306 for time 304 in an embodiment that shows the expected exhaust temperature change over time as a function of specific operating conditions. The solid line shown shows a specific temperature value at each time point, but this default value has some tolerance to provide the temperature range at each time point, i.e., the maximum and minimum temperature values at each time point. Should be easily understood. Accordingly, the default parameter range 306 of FIG. 3 shows the expected exhaust temperature based on the specific driving condition of the vehicle. Thus, the default parameter range 306 defines the temperature range of the expected exhaust temperature under normal operating mode.

  A broken line 308 in FIG. 3 shows a measured parameter value 308 in an example of the exhaust temperature measured at different time points. The measured temperature 308 is lower than the expected temperature 306 during substantially the entire period shown in FIG. However, at a particular point in time, the measured temperature 308 is increasing with respect to the expected temperature 306. A difference 30 between the measured temperature 308 and the expected temperature 306 is measured. Thus, when the difference 30 between the measured temperature 308 and the predicted temperature 306 is greater than the threshold temperature value, it is determined that the internal combustion engine does not indicate a normal operation mode, that is, the internal combustion engine indicates an abnormal operation mode. The The determination that the internal combustion engine indicates an abnormal operation mode may be based on the fact that the measured temperature is higher than the upper limit value of the temperature range, instead of comparing the difference 30 with a threshold value. For this reason, it is sufficient that the temperature is higher than expected in order to determine that the internal combustion engine exhibits an abnormal operation mode.

  Although FIG. 3 illustrates and describes the exhaust temperature, other parameters, such as crankcase pressure, engine speed, etc. are of course also useful to determine whether the internal combustion engine is in a normal or abnormal operating mode. These parameters can be measured and compared individually or in combination with each other.

  When it is determined that the measured exhaust temperature is higher than normal, that is, the difference 30 between the measured exhaust temperature 308 and the expected exhaust temperature 306 is greater than a predetermined threshold temperature value, the crankcase does not indicate a normal operation mode. Determined. Therefore, the internal combustion engine exhibits an abnormal operation mode. Accordingly, referring back to FIG. 2, the control unit 211 outputs a signal to the valve 210 so that the valve 210 is in a closed state in which the leaked crankcase fluid from the crankcase 217 cannot pass through the valve 210. . The leaky crankcase fluid is then directed to the relief valve 208 instead. The relief valve 208 is in a normal closed state, which means a normal state in which leaked crankcase fluid cannot pass. However, when the valve 210 is closed, the relief valve 208 is exposed to the pressure increased by the pressure from the leaking crankcase fluid. When the pressure of the relief valve 208 exceeds a certain limit, the relief valve 208 is placed in an open state, thereby leading leakage crankcase fluid to the ambient environment of the internal combustion engine 100 via the relief valve 208.

  Finally, reference is made to FIG. 4 showing a flowchart of a method according to an exemplary embodiment of the present invention. According to the first step of the method, the operating parameter value is measured in S1. Thereby, the parameter value of the internal combustion engine is measured. Since it is clear from the inventive concept of the present application that the parameter value is measured when the engine is running, the parameter value can be measured continuously during operation of the internal combustion engine. Thereafter, the parameter value 308 measured in S1 is compared to a predetermined parameter range in S2. The predetermined parameter range 306 is the same parameter range as measured in the previous step, and is a range that defines the operation mode of the internal combustion engine. Thus, the predetermined parameter range 306 depends on the specific operation of the vehicle and defines an operation mode based on this specific operation of the vehicle. For example, the default temperature range 306 described and illustrated in the exemplary embodiment with respect to FIG. 3 is different percentage values and temperatures when climbing a steep slope as compared to when the vehicle is traveling on a straight, flat road. It can have at least one of the values.

  Thereafter, in S3, it is determined whether the internal combustion engine is in an operation mode. This determination is made by comparing the measured parameter value 308 with a predetermined parameter range 306. Referring back to the example shown in FIG. 3, the difference 30 between the measured temperature 308 and the predetermined parameter range 306, i.e. the expected exhaust temperature range, is higher than a predetermined threshold at some point. At this point in time, it is determined that the internal combustion engine is not in the operation mode, that is, indicates an abnormal operation mode.

  The method then continues with directing a leaked crankcase fluid from the crankcase 217 of the internal combustion engine 100 to the intake air of the internal combustion engine at S4 if it is determined that the internal combustion engine is in an operating mode. According to an exemplary embodiment, the step of directing the leaky crankcase fluid is to position the valve 210 in an open state so that the leaky crankcase fluid can be directed from the crankcase 217 via the valve 210 to the internal combustion engine 100. To be executed.

  However, if the internal combustion engine is not in the operating mode, the leaky crankcase fluid is instead directed to the periodic environment of the internal combustion engine at S5. According to an exemplary embodiment, this step is performed by the leakage crankcase fluid to the ambient environment of the internal combustion engine via a relief valve 208 that is forced open by pressure exposed to the leakage crankcase fluid. It is executed by closing the valve 210 so as to be guided.

  It should be noted that the present invention works equally well by switching the position of valve 210 and relief valve 208. In such a case, the valve 210 is in a closed position to direct the leaked crankcase fluid through the relief valve 208 to the intake air of the internal combustion engine, and the leaked crank from the crankcase 217 to the surrounding environment of the internal combustion engine 100. Should be in the open position to direct fluid.

  When the valve 210, the control unit 211, and the bypass valve 216 are removed from the crankcase ventilation system described above, the crankcase ventilation system includes only the oil mist separator 204 and the relief valve 208. In such a case, leaky crankcase fluid is directed from the crankcase 217 to the intake air 203 of the internal combustion engine 100 during the normal operating mode. However, if the conduit 209 is frozen or clogged, for example, due to the low temperature at which the vehicle is traveling, the leaked crankcase fluid is prevented from being directed to the intake air 203 of the internal combustion engine. When the pressure rises and the pressure exceeds a certain threshold, the relief valve 208 is located in the open state and guides the leaked crankcase fluid through. This transforms the crankcase ventilation system from a closed crankcase ventilation system to an open crankcase ventilation system so that the crankcase ventilation system is released.

  It should be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings. Rather, those skilled in the art will recognize many changes and modifications that may be made within the scope of the appended claims. For example, the bypass valve described above is not essential to the overall function of the crankcase ventilation system. Also, the crankcase ventilation system should not be construed as limited to the use of an oil mist separator. The present invention works equally well without an oil mist separator or with other components that replace the oil mist separator and provide similar functionality to the system.

  The present invention relates to a method for removing leaked crankcase fluid from a crankcase of an internal combustion engine. The present invention also relates to a crankcase ventilation system and a control unit for controlling an electrically controlled valve of the crankcase ventilation system. The present invention is applicable to vehicles, particularly large vehicles such as trucks. However, although the present invention has been described mainly with respect to trucks, the present invention is of course applicable to internal combustion engines used in other types of vehicles such as passenger cars, industrial construction machines, wheel loaders, and the like. .

  A frequent problem with various types of internal combustion engines is that vapor leakage occurs in the crankcase during operation from the combustion process of the engine. These vapor leaks need to be handled in a sufficient and efficient manner so that the leaks are discharged from the crankcase. Since this adversely affects the environment, provides safety issues and adversely affects fuel consumption, it may not be appropriate to redirect vapor to the fuel tank and not to the environment. For this reason, it is desirable to introduce vapor leakage directly into the internal combustion engine so that it can be safely burned and partially used for power generation.

  According to an example, WO 2012/171593 discloses a fuel system for supplying fuel vapor to an internal combustion engine. The fuel system includes a housing that is refilled with lubricant at a constant fill level. During operation of the internal combustion engine to which the fuel system is connected, fuel vapor from the housing is introduced into the combustion chamber of the internal combustion engine. The system further includes a drain valve and a lubricant supply valve. When the engine is not operating, i.e. when the engine is stopped, these valves close, thus preventing fuel leakage from the housing. As a result, when the engine stops due to insufficient negative pressure at the intake port of the engine, the fuel vapor discharge may not function, so WO2012 / 171593 reduces the risk of oil leakage when the engine stops To solve the problem.

  However, the invention disclosed in WO2012 / 171593 requires further improvements, for example with respect to enhancing functionality and oil supply control.

US2011 / 0048391 relates to a breather system for a crankcase of an internal combustion engine. The system includes a pressure regulator that allows gas to enter a discharge conduit that can be directed to the atmosphere or redirected to the intake manifold of the engine.

  US 3372585 relates to a pressure warning system and a relief valve for a crankcase of an internal combustion engine. The system includes a valve assembly provided between a crankcase and a crankcase breather pipe.

International Publication No. 2012/171593 Pamphlet US Patent Application Publication No. 2011/0048391 US Pat. No. 3,372,685

  It is an object of the present invention to provide a method for removing leaked crankcase fluid formed in a crankcase of an internal combustion engine. The object is at least partly achieved by the method according to claim 1.

  According to a first aspect of the present invention, a method is provided for removing leaked crankcase fluid from a crankcase of an internal combustion engine during operation of the internal combustion engine. The method includes the steps of measuring an operating parameter value of the internal combustion engine, and a predetermined parameter that defines the operating mode of the internal combustion engine to determine whether the measured operating parameter value is in the operating mode. Comparing the range, guiding the leaked crankcase fluid from the crankcase to the intake of the internal combustion engine when it is determined that the internal combustion engine is in the operating mode, and the internal combustion engine not in the operating mode The leakage of the crankcase fluid from the crankcase to the ambient environment of the internal combustion engine.

  The term “operating parameter” is to be interpreted in the following as a parameter of the internal combustion engine, measured when the internal combustion engine is running, ie when the internal combustion engine is operated, throughout the entire description. . Also, the term “default parameter range” refers to a parameter range according to a measured parameter value, for example, so that a comparison between an operating parameter value and a default parameter range is made for similar parameters. Should be interpreted. Further, according to an exemplary embodiment, the predetermined parameter range is determined by the engine as expected under certain conditions when the engine is operating in normal operation, i.e. at the particular point in time when the measurement was made. Should be construed as the range defining the mode of operation of the engine.

  Also, the term “leaky crankcase fluid” should not be construed as being limited to a particular phase or type of fluid. The leaky crankcase fluid may be in the gas phase or liquid phase. The leaky crankcase fluid can include, for example, blow-by gas, fuel vapor, oil mist, and the like. Furthermore, the leaky crankcase fluid is the fluid generated in the crankcase during operation of the internal combustion engine, i.e. during the combustion process.

  As an example, as described below, for example, when the parameter is related to the exhaust temperature, the method according to the present invention measures the exhaust temperature at a specific time. The measured exhaust temperature is then compared with a predetermined parameter range defining the operating mode of the internal combustion engine, which in a particular example is the temperature range in which the exhaust is expected to be exposed under current engine operating conditions. The In this example, therefore, the operating mode is a predetermined temperature range. If the measured temperature is not within the range, it is determined that the internal combustion engine is not in the operating mode, and the leaked crankcase fluid is directed to the environment surrounding the internal combustion engine instead of the intake air of the internal combustion engine.

  It should be readily understood that the predetermined parameter range can be changed depending on the specific parameters measured. In practice, the range can be made small enough so that it can be considered a specific value.

  The present invention directs leakage crankcase fluid from the crankcase to one of the intake air of the internal combustion engine or the surrounding environment of the internal combustion engine so that it is excessive and controlled with respect to the internal combustion engine even when the engine is not operating in normal operating conditions. Not based on insights that can prevent fuel inhalation. Therefore, the present invention has the advantage that combustion of crankcase leakage of the internal combustion engine is enabled, and power is generated and vehicle emissions can be kept low in the normal operation mode of the internal combustion engine. The present invention provides an efficient engine runaway protection system and allows safe use of a fuel vent-free design. Thus, the crankcase ventilation system is provided to direct leaked crankcase fluid to one of the intake air of the internal combustion engine or the surrounding environment of the internal combustion engine, depending on engine conditions.

  Also, the ambient environment of the internal combustion engine should be interpreted as a position outside the engine and its associated components. This location does not necessarily have to be ambient air, for example, but can be similar to a waste oil collection device or other suitable arrangement for collecting fuel.

  According to an exemplary embodiment, when the internal combustion engine is in the operating mode, it can be determined that the internal combustion engine indicates the normal operating mode.

  In this way, the method distinguishes between operating modes in which the engine is operating as expected, i.e. normal operating modes, and operating modes in which the engine is not operating as expected, i.e. abnormal operating modes. Can do.

  According to an exemplary embodiment, the engine can exhibit a normal operating mode if the measured operating parameter value is within a predetermined parameter range. The advantage is that a well-defined spectrum is provided that the measured parameter value should take in order to determine that the engine exhibits a normal mode of operation. If the engine parameter value exceeds the upper limit value of the range, it is determined that the engine does not indicate a normal operation mode, that is, indicates an abnormal operation mode. Similarly, if the operating parameter value is lower than the lower limit value of the predetermined parameter range, it can be determined that the internal combustion engine does not indicate the normal operating mode. The predetermined parameter range may be, for example, a range extending from a lower end point value that is zero to a certain allowable upper limit value. In such a case, if the measured parameter value exceeds the range, the engine indicates an abnormal operation mode. Thus, the range is defined by an upper threshold, and if the measured operating parameter value exceeds the upper threshold, the engine indicates an abnormal operating mode. According to another example, the range can be a specific value with a predetermined tolerance so that the normal operating mode is defined as being within tolerance.

  According to an exemplary embodiment, the step of directing leaked crankcase fluid from the crankcase to the intake air of the internal combustion engine can be performed by controlling a valve.

  This makes it possible to control the valve so that the leaked crankcase fluid can pass through the valve, or in the closed state where the leaky crankcase fluid cannot pass through the valve. The valve can be controlled by a control unit that further receives information related to the measured parameter value. This allows the control unit to control the valve to open or close depending on the received measured parameter value and the comparison made between the measured parameter value and the predetermined parameter range. it can. For this reason, the control unit can also determine a predetermined parameter range. Alternatively, the control unit may be provided with data relating to the predetermined parameter range from the other control unit (s) of the vehicle. According to one example, the valve is normally in the open state.

  According to an exemplary embodiment, the valve can be located downstream of the crankcase such that the valve is disposed in fluid communication with the intake of the internal combustion engine.

  According to an exemplary embodiment, the step of directing the leaked crankcase fluid from the crankcase to the ambient environment of the internal combustion engine includes from the crankcase fluid in a relief valve disposed in fluid communication between the crankcase and the ambient environment. This can be done by controlling the valve so that the pressure exceeds a predetermined threshold limit.

  The relief valve can desirably be controlled by the pressure to which it is exposed. This prevents leakage crankcase fluid from passing through the valve, i.e., controlling the valve so that the valve is in the closed position, the pressure of the relief valve will eventually be in the open position. To the size you want. Accordingly, the relief valve is desirably located in fluid communication between the crankcase and the valve.

  The relief valve, of course, instead of the aforementioned automatically pressure controlled valve, when leaked crankcase fluid is led from the crankcase to the surrounding environment, the control unit controls the relief valve to open it, It can be controlled by the control unit so that the leaky crankcase fluid passes.

  According to an exemplary embodiment, the operating parameter value may be one of crankcase pressure, engine speed, and exhaust temperature, or any combination thereof.

  These parameters of the internal combustion engine are well known and easy to measure. Also, if these parameter values are not within the range defining the normal operating mode, the leaked crankcase fluid from the crankcase has characteristics that are not suitable for being provided to the internal combustion engine. It should be readily understood that depending on the specific parameters, measurements need to be made at specific locations on the engine. For example, the exhaust temperature may be different at different positions in the exhaust path, so it is important to measure the exhaust temperature at a predetermined temperature range position, that is, a position corresponding to a position that defines a normal temperature range. It is.

  According to a second aspect of the present invention, a crankcase ventilation system is provided for removing leaked crankcase fluid from a crankcase of an internal combustion engine. The crankcase ventilation system includes a valve configured to be in fluid communication with a crankcase of an internal combustion engine and an intake air of the internal combustion engine, and a control unit connectable to the valve. The engine operating parameter value is received, and the received operating parameter value is compared with a predetermined parameter range that defines the operating mode of the internal combustion engine to determine whether the internal combustion engine is in the operating mode, and the internal combustion engine is in the operating mode. Is determined, the valve is controlled to guide leakage crankcase fluid from the crankcase to the intake of the internal combustion engine, and when it is determined that the internal combustion engine is not in the operation mode, the valve is controlled to Configured to direct leaked crankcase fluid to the surrounding environment.

  An advantage of the system according to the second aspect of the present invention is that a combination of open and closed crankcase ventilation systems is provided. Therefore, if the leaked crankcase fluid is directed to the intake air of the internal combustion engine, the crankcase ventilation system will be a closed crankcase ventilation system, while if the leaked crankcase fluid is directed to the surrounding environment, the crankcase ventilation will be The system is an open crankcase ventilation system.

  According to an exemplary embodiment, the control unit can be configured to place the valve in an open state when it is determined that the internal combustion engine is in an operating mode. As a result, the crankcase fluid is guided from the crankcase through the valve to the intake air of the internal combustion engine.

  According to an exemplary embodiment, the crankcase ventilation system further comprises a relief valve configured to be placed in fluid communication between the crankcase and an outlet to the ambient environment of the internal combustion engine, wherein the internal combustion engine operates. When it is determined that the mode is not set, leakage crankcase fluid from the crankcase is configured to be guided through the relief valve.

  Therefore, when the valve is in the closed state, the leaked crankcase fluid is guided to the relief valve, and when the pressure of the relief valve exceeds the threshold pressure, the relief valve opens and the leaky crankcase fluid opens. The relief valve is controlled by a valve that is directed to the surrounding environment through the relief valve.

  According to an exemplary embodiment, the crankcase ventilation system further comprises an oil mist separator and the valve is located downstream of the oil mist separator.

  According to an exemplary embodiment, the valve can form an integrated part of an oil mist separator. This eliminates the need for individual connection points for the valve, for example, to the vehicle frame. Therefore, integrating the crankcase ventilation system into the oil mist separator does not involve any additional changes to the vehicle connecting the oil mist separator, thus reducing the overall cost of the crankcase ventilation system.

  The relief valve can also be located downstream of the oil mist separator. According to an exemplary embodiment, the relief valve can form part of an oil mist separator.

  By placing the crankcase ventilation system in combination with an oil separator, the leaked crankcase fluid from the crankcase is relatively clean and removes particles that can adversely affect the environment. Thus, providing an oil mist separator offers the advantage of reducing the need for external or additional waste oil collection devices or other devices for collecting fuel.

  According to an exemplary embodiment, the crankcase ventilation system may further comprise a pilot valve configured to position the valve in an open or closed state. According to an exemplary embodiment, the pilot valve can be connectable to the control unit and is configured to position the valve in an open state or a closed state in response to a signal received from the control unit. be able to. Further, according to an example, the pilot valve can be configured to position the valve in an open state or a closed state by pressure generated by intake air of the internal combustion engine.

  The advantage of using a pilot valve is that the pilot valve further controls the opening and closing of the valve.

  The pilot valve can also control other energy sources of the vehicle, such as an engine air brake system.

  According to an exemplary embodiment, the crankcase ventilation system may further comprise a bypass valve disposed in fluid communication between the valve and the intake air of the internal combustion engine.

  The bypass valve can further prevent unwanted leaky crankcase fluid from sucking into the internal combustion engine. This allows the bypass valve to operate as a backup valve in case the valve does not function properly. The bypass valve is adapted to be partially closed when the difference between the crankcase pressure and the intake air pressure of the internal combustion engine is greater than a predetermined threshold pressure value.

  The further effects and features of this second aspect are largely similar to those described above with respect to the first aspect of the present invention.

  According to a third aspect of the present invention, there is provided a control unit that can be electrically connected to a valve of a crankcase ventilation system of an internal combustion engine. The control unit receives the operating parameter value of the internal combustion engine, compares the received operating parameter value with a predetermined parameter range that defines the operating mode of the internal combustion engine, determines whether the internal combustion engine is in the operating mode, When it is determined that the engine is in the operation mode, the valve is controlled to guide the leaked crankcase fluid from the crankcase to the intake air of the internal combustion engine. Configured to direct leaked crankcase fluid to the environment.

  The effects and features of this third aspect are largely similar to those described above with respect to the first and second aspects of the present invention.

  According to a fourth aspect of the present invention there is provided an internal combustion engine comprising a crankcase ventilation system according to any of the exemplary embodiments described above.

  The effects and features of this fourth aspect are largely similar to those described above with respect to the first, second and third aspects of the present invention.

  According to a fifth aspect of the present invention, a crankcase ventilation system is provided for removing leaked crankcase fluid from a crankcase of an internal combustion engine. The crankcase ventilation system is positioned downstream of the crankcase, and is configured to be disposed in fluid communication between the crankcase and the intake air of the internal combustion engine, and is positioned downstream of the oil mist separator. A mist separator, a relief valve configured to be disposed in fluid communication with the intake air of the internal combustion engine and the surrounding environment of the internal combustion engine.

  The advantage of the fifth aspect of the present invention is that, for example, when the crankcase pressure rises due to malfunction of the crankcase ventilation system, the relief valve is positioned in the open state by the increased fluid pressure to which the relief valve is exposed. As a result, when the relief valve is in the open state, the crankcase pressure is reduced, and the vehicle can function properly. Further, the fifth aspect of the present invention is not able to guide the leaked crankcase fluid to the intake air of the internal combustion engine by the frozen conduit, so that, for example, when the conduit to the intake air of the internal combustion engine is frozen due to a cold air condition. Advantageously, the relief valve is exposed to elevated pressure, which automatically places it in an open state and directs leaky crank fluid to the surrounding environment.

  Thus, a fifth aspect of the present invention provides a closed crankcase ventilation system that can be automatically transformed into an open crankcase ventilation system. Thus, the fifth aspect allows the use of a closed crankcase ventilation system even in cold climates where it is desired to use an open crankcase ventilation system in advance.

  The above solution for a closed crankcase ventilation system utilizes a pressure sensor that warns the driver that the crankcase pressure is rising. If the driver does not reduce the crankcase pressure, the vehicle cannot function properly and must transition to a “limp home mode” where it can be secured.

  The fifth aspect of the invention can of course be combined with any of the features described above with respect to the first, second, third and fourth aspects of the invention. The advantages of such a feature in combination with the fifth aspect are largely similar to those described above.

  Additional features and advantages of the invention will be apparent from a review of the appended claims and the following description. Those skilled in the art will appreciate that different features of the present invention can be combined to create embodiments other than those described below without departing from the scope of the present invention.

  The foregoing will be better understood through the following exemplary and non-limiting detailed description of exemplary embodiments of the invention, as well as additional objects, features and advantages of the invention. .

1 is a side view of a vehicle equipped with an internal combustion engine equipped with a crankcase ventilation system according to an exemplary embodiment of the present invention. 1 is a schematic diagram of a crankcase ventilation system according to an exemplary embodiment of the present invention. FIG. It is a figure which shows an example of the temperature measured as a function of time, and predetermined temperature. 4 is a flowchart illustrating method steps according to an exemplary embodiment of the present invention.

  The invention will now be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the invention. However, the present invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for thorough and completeness. Like reference numerals refer to like components throughout the description.

  With particular reference to FIG. 1, there is provided a vehicle 1 equipped with an internal combustion engine 100 with a crankcase ventilation system according to the present invention. The vehicle 1 shown in FIG. 1 is a truck in which an inventive internal combustion engine 100 and a crankcase ventilation system, which will be described in detail below, are particularly suitable.

  FIG. 2 illustrates an engine system according to an exemplary embodiment of the present invention. The engine system includes a fuel system 201. The fuel system 201 can contain any fuel suitable for a particular engine type. Accordingly, the fuel system 201 can include diesel fuel, gasoline, ethanol, dimethyl ether (DME), and the like. The present invention should therefore not be limited to the specific fuel type driving the engine. The engine system also includes a cylinder arrangement 202 having a crankcase 217 that houses a crankshaft connected to a plurality of pistons via respective connecting rods. The fuel from the fuel tank 201 is guided to the engine via the oil trap 214. According to an example, the additional oil trap 215 may be located between the oil trap 214 and the fuel tank 201 as shown in FIG. The engine system also includes a crankcase ventilation system 206, which will be described in detail below, and a turbo unit including a turbine and a compressor. More specifically, the conduit 209 connects the crankcase ventilation system 206 to the internal combustion engine through the intake 203 and even the inlet of the internal combustion engine.

  Reference is now made to the crankcase ventilation system 206 of the present invention shown in FIG. According to the non-limiting example shown in FIG. 2, the crankcase ventilation system 206 includes an oil mist separator 204, a relief valve 208, a valve 210 electrically connected to the control unit 211, and an optional bypass valve 216. And comprising. The oil mist separator 204 is connected to the blow-by passage 205 and is disposed downstream of the crankcase. The relief valve 208 is further disposed downstream of the oil mist separator 204 in fluid communication between the oil mist separator 204 and the environment surrounding the internal combustion engine. Relief valve 208 should be construed as a valve that is open when exposed to a pressure that exceeds a predetermined pressure limit. The valve 210 is disposed downstream of the oil mist separator 204 and fluidly communicates the oil mist separator and the intake air 203 of the internal combustion engine. Finally, an optional bypass valve 216 is located downstream of the valve 210 and provides fluid communication between the valve 210 and the intake air 203 of the internal combustion engine.

  Further, the valve 210 may be a controllable valve positioned in a valve open state or a valve closed state by a signal from the control unit 211. The controllable valve can be, for example, a two-way valve.

  The function of the crankcase ventilation system 206 and related methods will now be described in more detail. For this reason, reference is made to FIGS.

  For example, when there is a fluid leak generated in the crankcase 217 from the combustion process of the internal combustion engine, the crankcase fluid leak is led out from the crankcase through the blow-by passage 205 and introduced into the mist oil separator 204. In the oil mist separator 204, the leaked crankcase fluid is supplied to the separation process so that the fluid exiting the oil mist separator 204 is free or relatively free from particles that can adversely affect the environment. Accordingly, the fluid leaving the oil mist separator 204 and entering the conduit 207 is relatively clean. The leaky crankcase fluid is then directed to valve 210 or relief valve 208.

  In order to determine if leaky crankcase fluid is to be directed through valve 210 or relief valve 208, the present invention determines whether the internal combustion engine is operating according to normal or abnormal operating modes. This determination is shown in FIG. 3 and gives an example related to exhaust temperature 302 relative to time 304. Accordingly, FIG. 3 shows the change in exhaust temperature over time when the vehicle is traveling. It should be noted that the graph shown in FIG. 3 is only useful for illustrative purposes.

  The solid line 306 in FIG. 3 shows the default parameter range 306 for time 304 in an embodiment that shows the expected exhaust temperature change over time as a function of specific operating conditions. The solid line shown shows a specific temperature value at each time point, but this default value has some tolerance to provide the temperature range at each time point, i.e., the maximum and minimum temperature values at each time point. Should be easily understood. Accordingly, the default parameter range 306 of FIG. 3 shows the expected exhaust temperature based on the specific driving condition of the vehicle. Thus, the default parameter range 306 defines the temperature range of the expected exhaust temperature under normal operating mode.

  A broken line 308 in FIG. 3 shows a measured parameter value 308 in an example of the exhaust temperature measured at different time points. The measured temperature 308 is lower than the expected temperature 306 during substantially the entire period shown in FIG. However, at a particular point in time, the measured temperature 308 is increasing with respect to the expected temperature 306. A difference 30 between the measured temperature 308 and the expected temperature 306 is measured. Thus, when the difference 30 between the measured temperature 308 and the predicted temperature 306 is greater than the threshold temperature value, it is determined that the internal combustion engine does not indicate a normal operation mode, that is, the internal combustion engine indicates an abnormal operation mode. The The determination that the internal combustion engine indicates an abnormal operation mode may be based on the fact that the measured temperature is higher than the upper limit value of the temperature range, instead of comparing the difference 30 with a threshold value. For this reason, it is sufficient that the temperature is higher than expected in order to determine that the internal combustion engine exhibits an abnormal operation mode.

  Although FIG. 3 illustrates and describes the exhaust temperature, other parameters, such as crankcase pressure, engine speed, etc. are of course also useful to determine whether the internal combustion engine is in a normal or abnormal operating mode. These parameters can be measured and compared individually or in combination with each other.

  When it is determined that the measured exhaust temperature is higher than normal, that is, the difference 30 between the measured exhaust temperature 308 and the expected exhaust temperature 306 is greater than a predetermined threshold temperature value, the crankcase does not indicate a normal operation mode. Determined. Therefore, the internal combustion engine exhibits an abnormal operation mode. Accordingly, referring back to FIG. 2, the control unit 211 outputs a signal to the valve 210 so that the valve 210 is in a closed state in which the leaked crankcase fluid from the crankcase 217 cannot pass through the valve 210. . The leaky crankcase fluid is then directed to the relief valve 208 instead. The relief valve 208 is in a normal closed state, which means a normal state in which leaked crankcase fluid cannot pass. However, when the valve 210 is closed, the relief valve 208 is exposed to the pressure increased by the pressure from the leaking crankcase fluid. When the pressure of the relief valve 208 exceeds a certain limit, the relief valve 208 is placed in an open state, thereby leading leakage crankcase fluid to the ambient environment of the internal combustion engine 100 via the relief valve 208.

  Finally, reference is made to FIG. 4 showing a flowchart of a method according to an exemplary embodiment of the present invention. According to the first step of the method, the operating parameter value is measured in S1. Thereby, the parameter value of the internal combustion engine is measured. Since it is clear from the inventive concept of the present application that the parameter value is measured when the engine is running, the parameter value can be measured continuously during operation of the internal combustion engine. Thereafter, the parameter value 308 measured in S1 is compared to a predetermined parameter range in S2. The predetermined parameter range 306 is the same parameter range as measured in the previous step, and is a range that defines the operation mode of the internal combustion engine. Thus, the predetermined parameter range 306 depends on the specific operation of the vehicle and defines an operation mode based on this specific operation of the vehicle. For example, the default temperature range 306 described and illustrated in the exemplary embodiment with respect to FIG. 3 is different percentage values and temperatures when climbing a steep slope as compared to when the vehicle is traveling on a straight, flat road. It can have at least one of the values.

  Thereafter, in S3, it is determined whether the internal combustion engine is in an operation mode. This determination is made by comparing the measured parameter value 308 with a predetermined parameter range 306. Referring back to the example shown in FIG. 3, the difference 30 between the measured temperature 308 and the predetermined parameter range 306, i.e. the expected exhaust temperature range, is higher than a predetermined threshold at some point. At this point in time, it is determined that the internal combustion engine is not in the operation mode, that is, indicates an abnormal operation mode.

  The method then continues with directing a leaked crankcase fluid from the crankcase 217 of the internal combustion engine 100 to the intake air of the internal combustion engine at S4 if it is determined that the internal combustion engine is in an operating mode. According to an exemplary embodiment, the step of directing the leaky crankcase fluid is to position the valve 210 in an open state so that the leaky crankcase fluid can be directed from the crankcase 217 via the valve 210 to the internal combustion engine 100. To be executed.

  However, if the internal combustion engine is not in the operating mode, the leaky crankcase fluid is instead directed to the periodic environment of the internal combustion engine at S5. According to an exemplary embodiment, this step is performed by the leakage crankcase fluid to the ambient environment of the internal combustion engine via a relief valve 208 that is forced open by pressure exposed to the leakage crankcase fluid. It is executed by closing the valve 210 so as to be guided.

  It should be noted that the present invention works equally well by switching the position of valve 210 and relief valve 208. In such a case, the valve 210 is in a closed position to direct the leaked crankcase fluid through the relief valve 208 to the intake air of the internal combustion engine, and the leaked crank from the crankcase 217 to the surrounding environment of the internal combustion engine 100. Should be in the open position to direct fluid.

  When the valve 210, the control unit 211, and the bypass valve 216 are removed from the crankcase ventilation system described above, the crankcase ventilation system includes only the oil mist separator 204 and the relief valve 208. In such a case, leaky crankcase fluid is directed from the crankcase 217 to the intake air 203 of the internal combustion engine 100 during the normal operating mode. However, if the conduit 209 is frozen or clogged, for example, due to the low temperature at which the vehicle is traveling, the leaked crankcase fluid is prevented from being directed to the intake air 203 of the internal combustion engine. When the pressure rises and the pressure exceeds a certain threshold, the relief valve 208 is located in the open state and guides the leaked crankcase fluid through. This transforms the crankcase ventilation system from a closed crankcase ventilation system to an open crankcase ventilation system so that the crankcase ventilation system is released.

  It should be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings. Rather, those skilled in the art will recognize many changes and modifications that may be made within the scope of the appended claims. For example, the bypass valve described above is not essential to the overall function of the crankcase ventilation system. Also, the crankcase ventilation system should not be construed as limited to the use of an oil mist separator. The present invention works equally well without an oil mist separator or with other components that replace the oil mist separator and provide similar functionality to the system.

Claims (21)

A method of removing leaked crankcase fluid from a crankcase (217) of the internal combustion engine (100) during operation of the internal combustion engine (100), comprising:
Measuring an operating parameter value (308) of the internal combustion engine (100) (S1);
Compare the measured operating parameter value (308) with a predetermined parameter range (306) defining an operating mode of the internal combustion engine (100) to determine whether the internal combustion engine is in an operating mode (S3). Performing step (S2);
Directing the leaked crankcase fluid from the crankcase (217) to the intake (203) of the internal combustion engine (S4) when it is determined that the internal combustion engine is in the operating mode;
Directing the leaked crankcase fluid from the crankcase (217) to the surrounding environment of the internal combustion engine (S5) when it is determined that the internal combustion engine is not in the operating mode;
With a method. When the internal combustion engine (100) is in the operation mode, it is determined that the internal combustion engine (100) indicates a normal operation mode.
The method of claim 1. The engine indicates a normal operating mode when the measured operating parameter value is within the predetermined parameter range (306);
The method of claim 2. The step (S4) of directing the leaked crankcase fluid from the crankcase (217) to the intake (203) of the internal combustion engine (100) is performed by controlling a valve (210).
4. A method according to any one of claims 1-3. The valve (210) of the crankcase (217) is arranged such that the valve (210) is placed in fluid communication between the crankcase (217) and the intake air (203) of the internal combustion engine (100). Located downstream,
The method of claim 4. The step (S5) of guiding the leaked crankcase fluid from the crankcase (217) to the ambient environment of the internal combustion engine (100) is disposed in fluid communication between the crankcase (217) and the ambient environment. In a relief valve (208), this is performed by controlling the valve (210) such that the pressure from the crankcase fluid exceeds a predetermined threshold limit.
6. A method according to any one of claims 1-5. The operating parameter value is one of crankcase pressure, engine speed and exhaust temperature, or any combination thereof.
7. A method according to any one of claims 1-6. A crankcase ventilation system (206) for removing leaked crankcase fluid from a crankcase (217) of an internal combustion engine (100) comprising:
A valve (210) configured to be placed in fluid communication between a crankcase (217) of the internal combustion engine (100) and an intake air (203) of the internal combustion engine (100);
A control unit (211) connectable to the valve (210);
With
The control unit (211)
Receiving an operating parameter value (308) of the internal combustion engine (100);
Comparing the received operating parameter value (308) with a predetermined parameter range (306) defining an operating mode of the internal combustion engine (100) to determine whether the internal combustion engine (100) is in the operating mode;
When it is determined that the internal combustion engine (100) is in the operation mode, the valve (210) is controlled to leak from the crankcase (217) to the intake air (203) of the internal combustion engine (100). Lead the crankcase fluid,
When it is determined that the internal combustion engine is not in the operating mode, the valve (210) is controlled to direct leakage crankcase fluid from the crankcase (217) to the ambient environment of the internal combustion engine (100);
A crankcase ventilation system (206) configured as described above. The control unit (211) is configured to position the valve (210) in an open state when it is determined that the internal combustion engine (100) is in the operation mode.
Crankcase ventilation system (206) according to claim 8. A relief valve (208) configured to be placed in fluid communication between the crankcase (217) and an outlet of the internal combustion engine (100) to the surrounding environment;
When it is determined that the internal combustion engine (100) is not in the operation mode, leakage crankcase fluid from the crankcase (217) is configured to be guided through the relief valve (208).
Crankcase ventilation system (206) according to claim 8 or claim 9. An oil mist separator (204);
The valve (210) is located downstream of the oil mist separator (204);
Crankcase ventilation system (206) according to any one of claims 8 to 10. The valve (210) forms part of the oil mist separator (204);
The crankcase ventilation system (206) of claim 11. The relief valve (208) is located downstream of the oil mist separator (204),
Crankcase ventilation system (206) according to claim 11 when dependent on claim 10. The relief valve (208) forms part of the oil mist separator (204);
Crankcase ventilation system (206) according to claim 11 when dependent on claim 10. Further comprising a pilot valve configured to position the valve (210) in an open state or a closed state;
Crankcase ventilation system (206) according to any one of claims 8 to 14. The pilot valve is connectable to the control unit (211) and responds to a signal received from the control unit (211) to position the valve (210) in the open state or the closed state. Configured as
The crankcase ventilation system (206) of claim 15. The pilot valve is configured to position the valve (210) in the open state or the closed state by the pressure generated in the intake air (203) of the internal combustion engine.
The crankcase ventilation system (206) of claim 15. A bypass valve (216) disposed in fluid communication between the valve (210) and the intake air (203) of the internal combustion engine (100);
Crankcase ventilation system (206) according to any one of claims 8 to 17. A control unit (211) electrically connectable to a valve (210) of a crankcase ventilation system (206) of an internal combustion engine (100),
Receiving an operating parameter value (308) of the internal combustion engine (100);
Comparing the received operating parameter value (308) with a predetermined parameter range (306) defining an operating mode of the internal combustion engine (100) to determine whether the internal combustion engine (100) is in the operating mode;
When it is determined that the internal combustion engine is in the operation mode, the valve (210) is controlled to cause leakage crankcase fluid from the crankcase (217) to the intake air (203) of the internal combustion engine (100). Guiding,
When it is determined that the internal combustion engine is not in the operating mode, the valve (210) is controlled to direct leakage crankcase fluid from the crankcase (217) to the ambient environment of the internal combustion engine (100);
A control unit (211) configured as described above.   An internal combustion engine (100) comprising the crankcase ventilation system (206) according to any one of claims 8-18. A crankcase ventilation system for removing leaked crankcase fluid from a crankcase (217) of an internal combustion engine (100) comprising:
An oil mist separator (204) positioned downstream of the crankcase (217) and configured to be placed in fluid communication between the crankcase (217) and the intake air (203) of the internal combustion engine (100). When,
Located downstream of the oil mist separator (204), the oil mist separator (204), the intake air (203) of the internal combustion engine (100) and the surrounding environment of the internal combustion engine (100) are arranged in fluid communication. A relief valve (208) configured as follows:
Crankcase ventilation system with.